The key to solving the 25-year riddle over the brutal murder of a schoolgirl less than a mile from her home lies within a small Norfolk community, police have said.

Johanna Young was just 14 years old when she left her home in Merton Road, Watton, on a cold and foggy night the day on December 23 1992.

Her body was found on Boxing Day less than a mile from her house, lying face down in a flooded pit on the edge of Wayland Wood.

Det Ch Insp Marie James, of the Norfolk and Suffolk Major Investigations Team, said: 'I'm convinced that somebody out there knows what happened to Johanna and the events that led to her death - and I'm convinced that the answer lies within the community of Watton.

'I would urge those people to please search their consciences, to please come forward and provide answers for the family.'

Johanna's parents Rob and Carol, who still live in Watton, first realised their daughter hadn't come home when her alarm clock rang at 6am on Christmas Eve but no-one was there to switch it off.

They believed she must have stayed with a friend due to the bad weather but when Johanna didn't arrive for her newspaper round at 7am, they called the police.

She had last been seen on Watton High Street near Mr Chippy, which is now called Little Gary's Plaice, at around 8pm on December 23.

Days later, after a heart-wrenching search and investigation, a dog walker found her shoes tucked neatly under a bush on Griston Road on Boxing Day afternoon.

He alerted the police, who found Johanna's body a few hundred yards away with her lower clothing removed and her jeans missing, although there was no evidence of a sexual motive.

A post-mortem examination revealed that she had died from drowning after suffering a fractured skull.

A witness has described spotting a couple leaning on a motorbike at the end of Griston Road who have never been identified.

Det Ch Insp James said: 'It was always a possibility, though never proven, that [the head injury] could have been caused by coming off a motorcycle.'

Johanna's ex-boyfriend was investigated and cleared at the time. Another young man from the town was arrested but was not charged.

Following the 21st anniversary appeal of Johanna's murder, Norfolk police had the 'best response' they had ever received from the public regarding a cold case which led to two more suspects being arrested in 2014. Once again though, there was not enough evidence to lead to a conviction.

The atmosphere in Watton after 25 years is still mournful. One resident, who remembered Johanna as a young girl and teenager, described how the entire town felt quiet following the schoolgirl's death.

She added: 'Johanna was a quiet and nice girl. It was incredibly sad.'

Police have now renewed their appeal for information in this case, which rocked the close-knit community of Watton and has tragically remained unsolved for a quarter of a century.

Det Ch Insp James said: 'Johanna Young is a daughter, a sister and a friend who continues to be dearly missed by those still struggling to come to terms with her death.

'They are left wondering what happened to her, what the events are which led to her death and who is responsible and always wondering if it is someone they knew.

'This time of year is particularly significant for Johanna's family - it's emotionally draining.

'Twenty-five years ago it was never established who was responsible for her death and the case remains open and we will follow up any new lines of inquiry.'

Anyone who has any information, even if it may seem small or insignificant, is urged to contact the Major Investigations Team on 101 or Crimestoppers anonymously on 0800 555111.